High contact resistance detection

ABSTRACT

A device includes an interface configured to couple a power source to the device. The interface includes a plurality of contacts including at least one first contact configured to couple a voltage bus of the power source to a voltage bus of the device, and at least one second contact configured to couple the voltage bus of the power source to a secondary bus of the device. The device further includes a detector configured to determine a contact resistance of the at least one first contact based on a first current associated with the voltage bus and a second current associated with the secondary bus.

RELATED APPLICATION

This application claims priority to and the benefit of U.S. ProvisionalApplication No. 62/382,162, entitled, “TYPE C HIGH CONTACT RESISTANCEPOLLUTION DETECTION,” filed Aug. 31, 2016, which is incorporated hereinby reference in its entirety.

FIELD

Embodiments relate to detecting contact resistance in a Universal SerialBus (USB) connector contact.

BACKGROUND

USB Type-C is a USB connector type that allows for higher voltage andcurrent capabilities than previous USB connector types. Due to theincreased current capabilities, connector contact resistance can be aconcern because of the potential for increased heat associated with anincrease in power dissipation in the connector contact. Excessivecontact resistance can cause over heating of the USB connector,resulting in possibly melting of the plastic components of the USBconnector and/or damage to the coupled computing device.

SUMMARY

In at least one general aspect, a device includes an interfaceconfigured to couple a power source to the device. The interfaceincludes a plurality of contacts including at least one first contactconfigured to couple a voltage bus of the power source to a voltage busof the device, and at least one second contact configured to couple thevoltage bus of the power source to a secondary bus of the device. Thedevice further includes a detector configured to determine a contactresistance of the at least one first contact based on a first currentassociated with the voltage bus and a second current associated with thesecondary bus.

In another general aspect, a method includes detecting a bus voltage ona first side of a contact of a connector interface, detecting the busvoltage on a second side of the contact of the connector interface,determining a voltage drop based on the bus voltage on the first side ofthe contact and the bus voltage on the second side of the contact, andreducing a current drawn from a power source based on the voltage drop.

In yet another general aspect, a USB TYPE-C connector includes a voltagebus trace coupled to a voltage bus of a power source, and an interfaceconfigured to couple the power source to a device. The interfaceincludes a plurality of contacts the plurality of contacts include atleast one voltage bus contact configured to couple the voltage bus traceto a voltage bus of the device, and at least one contact configured tocouple the voltage bus trace to a secondary bus of the device.

Implementations can include one or more of the following features. Forexample, the detector can be configured to generate a voltage dropgenerated based on a current associated with the voltage bus and acurrent associated with the secondary bus, determine if the voltage dropexceeds a reference value, and in response to determining the voltagedrop exceeds the reference value, trigger a reduction of a current drawnfrom the power source. The detector can include a current senseamplifier configured to generate a voltage drop generated based on acurrent associated with the voltage bus and a current associated withthe secondary bus, and a comparator configured to compare the voltagedrop to a reference value, and communicate a result of the comparing ofthe voltage drop to the reference value to a processor.

For example, the device can further include a battery, a switchingcharger configured to reduce a voltage to a level supported by thebattery, a bypass switch configured to bypass the switching charger, anda processor configured to select the switching charger or the bypassswitch based on a voltage associated with the power source. Theinterface can use a universal serial bus (USB) TYPE-C standard. Thedevice can further include a processor configured to determine an amountof current to draw from the power source based on a capability signalreceived from the power source, instruct one of a switching charger or abypass switch to draw the amount of current from the power source, andinstruct one of the switching charger or the bypass switch to reduce theamount of current to draw from the power source based on a communicationreceived from the detector.

For example, the device can further include a processor configured toinstruct one of a switching charger or a bypass switch to draw currentfrom the power source, and instruct one of the switching charger or thebypass switch to terminate the drawing of the current from the powersource based on a communication received from the detector. Thesecondary bus can include a high impedance input to the detector. Thedevice can further include a processor configured to cause a couplingand decoupling of a voltage bus trace associated with the voltage bus ofthe power source to the secondary bus of the device.

Implementations can include one or more of the following features. Forexample, the method can include comparing the voltage drop to areference voltage. The voltage drop can correspond to a contactresistance of the contact. The contact can be a first contact, themethod further includes one of coupling or decoupling the bus voltage toa second contact on the second side of the contact. The method caninclude comparing the voltage drop to a reference value, andcommunicating a result of the comparing of the voltage drop to thereference value to a processor. The method can include determining ifthe voltage drop exceeds a reference value, and in response todetermining the voltage drop exceeds the reference value, triggering thereducing of the current drawn from the power source. The method caninclude determining if the voltage drop exceeds a reference value, andin response to determining the voltage drop exceeds the reference value,terminating the current draw from the power source. The method caninclude selecting one of a switching charger or a bypass switch for usein charging a battery based on a voltage associated with the powersource.

Implementations can include one or more of the following features. Forexample, the USB TYPE-C connector can include a switch configured tocouple the voltage bus trace to the at least one contact.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a block diagram illustrating a structure of a serial interfaceaccording to at least one example embodiment.

FIG. 2 is a block diagram illustrating a system according to at leastone example embodiment.

FIG. 3 is another block diagram further illustrating the system of FIG.2 according to at least one example embodiment.

FIG. 4 is a flowchart illustrating a method for preventing an overtemperature condition while charging a device according to at least oneexample embodiment.

It should be noted that these Figures are intended to illustrate thegeneral characteristics of methods, structure and/or materials utilizedin certain example embodiments and to supplement the written descriptionprovided below. These drawings are not, however, to scale and may notprecisely reflect the precise structural or performance characteristicsof any given embodiment, and should not be interpreted as defining orlimiting the range of values or properties encompassed by exampleembodiments. For example, the relative positioning of regions and/orstructural elements may be reduced or exaggerated for clarity. The useof similar or identical reference numbers in the various drawings isintended to indicate the presence of a similar or identical element orfeature.

DETAILED DESCRIPTION OF THE EMBODIMENTS

Overheating of the universal serial bus (USB) connector is typicallydetected using a temperature measuring device (e.g., thermistor) locatedproximate to a contact or on the body of the USB connector. However,temperature measuring devices can provide temperature readings tooslowly for a computing device to take action (e.g., reduce current) toprevent damage to components of the USB connector and/or damage to thecoupled computing device.

In example embodiments described herein, a modified USB connector can beconfigured to allow the coupled computing device to determine a contactresistance of the USB connector. The coupled computing device caninclude components configured to determine contact resistance using amodified (e.g., as compared to a standard) USB connector. Further, thecomputing device can be configured to take action (e.g., execute aprocess) to prevent overheating of the USB connector based on thedetermined contact resistance (e.g., without using a temperaturemeasuring device). Thus preventing damage to components of the USBconnector and/or damage to the coupled computing device due tooverheating.

While example embodiments may include various modifications andalternative forms, embodiments thereof are shown by way of example inthe drawings and will herein be described in detail. It should beunderstood, however, that there is no intent to limit exampleembodiments to the particular forms disclosed, but on the contrary,example embodiments are to cover all modifications, equivalents, andalternatives falling within the scope of the claims. Like numbers referto like elements throughout the description of the figures.

FIG. 1 is a block diagram illustrating a structure of serial interfaceaccording to at least one example embodiment. The serial interface caninclude a plurality of contacts and be configured to couple a powersource to a device. The plurality of contacts can include at least onevoltage bus contact configured to couple a voltage bus trace to avoltage bus of the device, and at least one contact configured to couplethe voltage bus trace to a secondary bus of the device. The device caninclude a detector configured to determine a contact resistance of theat least one voltage bus contact based on a first current associatedwith the voltage bus and a second current associated with the secondarybus

As shown in FIG. 1, the serial interface 100 can include a plurality ofcontacts (or pins) A1 to A12 and B1 to B12. Contact A1, A12, B1 and B12can be ground contacts. Contacts A2 and A3 (TX1+, TX1−), B2 and B3(TX1+, TX1−) can form differential pairs in a high speed transmission(TX or transmit end) line or path. Contacts A10 and A11 (RX2−, RX2+),B10 and B11 (RX1−, RX1+) can form differential pairs in a high speedtransmission (RX or receive end) line or path. Contacts A4, A9, B4 andB9 can be bus power (V_(bus)) contacts. Contacts A5 and B5 (CC1, CC2)can form a configuration channel. The configuration channel (CC) is alow speed communication channel used to communicate configurationparameters. For example, CC can be used to detect attachment of USBports, to establish source and sink roles for devices (e.g., duringpower transfer), to establish V_(bus) configuration (e.g., voltage andcurrent), and the like. Contacts A6, A7, B6 and B7 (D+, D−) can form adifferential pair in a transmission line or path. Contacts A8 and B8 canform a channel as a side band use (SBU). SBU is not used in normal USBoperations. However, SBU can be used in alternate USB modes. Forexample, in an alternate USB mode, SBU can be used as a video channel,an audio channel and the like. As shown in FIG. 1, the serial interface100 can further include an outer body or shell 105. The outer body orshell 105 can be configured to help hold (e.g., maintain, house) a matedpair of interfaces. Further, in an implementation of a plug (or male)interface, element 110 can be a printed circuit board on which thecontacts are formed which can be configured to be inserted into acorresponding receptacle.

The serial interface 100 can be a USB Type-C connector. The USB Type-Cconnector is a USB connector type that allows for higher voltage andcurrent capabilities than previous USB connector types. Previous USBconnector types allowed for currents up to three amps. USB Type-Cstandards allow for currents of five amps and possibly up to eight ampsor higher. Due to the increased current capabilities, connector contactresistance is a concern because of the potential for increased heatassociated with an increase in power dissipation.

As shown in FIG. 1, the serial interface 100 can further include a firstshort 115 and a second short 120. The first short 115 and the secondshort 120 can short the bus power (V_(bus)) contacts to the side banduse (SBU) contacts. The first short 115 and the second short 120 can beused (e.g. by a coupled computing device) to determine a voltage dropacross the bus power contacts. The voltage drop across the bus powercontacts can be used to determine a contact resistance for the bus powercontacts.

The first short 115 and the second short 120 can be a contact to contactshort and/or a contact to a corresponding bus, trace or path on theprinted circuit board (e.g., element 110) short. The first short 115 andthe second short 120 can be a variable short. In other words, the firstshort 115 and the second short 120 can be switches that when closed forma short between the bus power (V_(bus)) contacts to the side band use(SBU) contacts and when open remove the short between the bus power(V_(bus)) contacts to the side band use (SBU) contacts. Although theshort is shown between the bus power (V_(bus)) contacts to the side banduse (SBU) contacts, the short can be between the bus power (V_(bus))contacts to another contact (e.g., D+, D−, or TX1+, TX1−, or RX1−,RX1+).

FIG. 2 is a block diagram illustrating a system according to at leastone example embodiment. As shown in FIG. 2, the system 200 can include apower converter 205 and a computing device 225. The power converter 205can be a travel adapter, a wall charger, a power brick, a battery, acomputing device, and the like. Therefore, the power converter 205includes wall plug 240 used to couple the power converter 205 to a powersource (e.g., a wall outlet). The power converter 205 can be configuredto provide power (e.g., voltage and current) to the computing device 225via cable assembly 245.

The computing device 225 can be any computing device (e.g., mobilephone, laptop, smart watch, and the like). The computing device 225 canbe configured for fast (e.g., quick, rapid, and the like) charging basedon a new USB standard. For example, the computing device 225, ifconfigured with fast charging capability, can be configured to draw alarger amount of power (e.g., more current and/or a higher voltage) fromthe power converter 205 as compared to older USB standards.

The computing device 225 can be configured to draw a fixed and/orvariable current and/or voltage. Connector A 210 and connector B 220 canbe a standard based connectors (e.g., USB TYPE-C). The power converter205 has a corresponding interface that connector A can plug into. Thecomputing device 225 has a corresponding interface that connector B canplug into. The cable 215, connector A and connector B together can be acable assembly 245.

The computing device 225 includes a detector 230. The detector 230 canbe configured to determine a contact resistance associated withconnector B exceeds a threshold value. In response to determining thecontact resistance associated with connector B exceeds a thresholdvalue, the detector 230 can be configured to cause the current drawnfrom the power converter 205 to be reduced (e.g., reduce current drawnby computing device 225) thus preventing damage to components ofconnector B and/or damage to the computing device 225 due to overheatingof connector B.

In an example implementation, connector A and connector B can be serialinterfaces. Accordingly, connector A (with or without first short 115and the second short 120) and connector B (with first short 115 and thesecond short 120) can include the structure of serial interface 100. Assuch, the power converter 205 can provide power to the computing device225 using the structure of serial interface 100. For example, the powerconverter 205 can provide power to the computing device 225 usingcontact A9, A4 and/or B9, B4 (V_(bus)) and A1, A12, B1 or B12 (GND) ofthe structure of serial interface 100.

FIG. 3 is a more detailed view of the components of FIG. 2. As shown inFIG. 3, the computing device 225 further includes a processor 305, aswitching charger 310, a bypass switch 315, a battery 320, and aninterface 350. The detector 230 includes a current sense amplifier 330and a comparator 335.

As shown in FIG. 3, the connector B further includes a short 340 and aninterface 345. The interface 345 includes a plurality of contacts (e.g.,including a first side of a contact or a cable assembly connector sideof a contact). The interface 345 can be one gender (e.g., plug or male)of the serial interface 100. The interface 350 includes a plurality ofcontacts (e.g., including a second side of a contact or a device side ofa contact). The interface 350 can be one gender (e.g., receptacle, jackor female) of the serial interface 100. At least one of the plurality ofcontacts of the interface 350 is a first contact 352A, 352B configuredto couple a voltage bus of the power source to a voltage bus of thedevice. At least one of the plurality of contacts of the interface 350is a second contact 354 configured to couple the voltage bus of thepower source to a secondary bus of the device. The contact resistancebetween interface 345 and interface 350 is represented by R_(con)(typically 5-10 mΩ).

The short 340 can be contact to contact and/or contact to acorresponding bus or path on the printed circuit board (e.g., element110). The short 340 can be a variable short. In other words, the short340 can be a switch that when closed form a short between the bus power(V_(bus)) contact to the side band use (SBU) contact and when openremove the short between the bus power (V_(bus)) contact to the sideband use (SBU) contact. Although the short is shown between the buspower (V_(bus)) contact to the side band use (SBU) contact, the shortcan be between the bus power (V_(bus)) contacts to another contact(e.g., D+, D−, or TX1+, TX1−, or RX1−, RX1+).

To charge the battery 320, current passes through the interface 350along a voltage bus to the switching charger 310 and the bypass switch315. The processor 305 can be configured to control the charging of thebattery 320 by controlling the switching charger 310 and the bypassswitch 315. The processor 305 can be configured to determine an amountof current to draw via the voltage bus from the power converter 205based on a host capability signal received from the power converter 205(e.g., via the CC path). If the voltage from the power converter 205 istoo high for the battery 320, the processor 305 can direct the currentthrough the switching charger 310 to buck (e.g., reduce) the voltagedown to a level supported by the battery 320. If the voltage from thepower converter 205 is at a level supported by the battery 320, thepower converter 205 can direct the current through the bypass switch 315to the battery 320 (e.g., for fast charging).

The current sense amplifier 330 is configured to directly measure theV_(bus) contact resistance by measuring a voltage drop across theV_(bus) contact (e.g., during high current charging). The current senseamplifier 330 is configured to detect current in the voltage bus or theV_(bus) path and a secondary bus or the V_(sbu) path and convert thecurrents to an output voltage. The output voltage can be based on (e.g.,proportional to) a difference between the current through the V_(sbu)path and the V_(bus) path. The connection between the voltage bus traceor the V_(bus) trace (e.g., a bus or path on the printed circuit boardportion of a connector) and the SBU pins (e.g., short 340) is configuredto enable the current sense amplifier 330 access to both sides (e.g.,computing device 225 side and connector B side) of the V_(bus)connection to determine (e.g., based on the sensed currents and/orvoltage drop) the contact resistance. As shown in FIG. 3, V_(bus) on theconnector B side is represented by V_(sbu) on the computing device 225side. V_(sbu) can have a high impedance input to the detector 230.Therefore, short 340 does not cause a current draw from the powerconverter 205. If the output of the current sense amplifier 330 exceedsthe reference (e.g., a threshold voltage or reference voltage) on thecomparator 335, the comparator 335 can communicate a signal (e.g., aninterrupt signal) to the processor 305. The processor 305 then modifiesthe charging process.

For example, the modification to the charging process can includelowering the current draw on V_(bus), or terminating the chargingprocess. The current sense amplifier 330 can detect a problem withoutthe waiting for the housing of connector B to reach high temperatures(e.g., through use of a thermistor). In other words, by measuring thevoltage drop across the V_(bus) contact the current sense amplifier 330can detect a high contact resistance and prevent an over temperaturecondition without the use of a temperature measuring device (e.g., athermistor). Measuring the voltage drop across the V_(bus) contact alsodetects the voltage drop faster than measuring the temperature and thususing the current sense amplifier 330 can allow the processor 305 tomodify the charging process faster than through use of a temperaturemeasuring device (e.g., a thermistor).

FIG. 4 is a flowchart illustrating a method according to at least oneexample embodiment. The steps described with regard to FIG. 4 may beperformed due to the execution of software code stored in a memoryand/or a non-transitory computer readable medium (e.g., memory includedin computing device 225) associated with an apparatus (e.g., as shown inFIGS. 2 and 3 (described above)) and executed by at least one processor(e.g., processor 305) associated with the apparatus. However,alternative embodiments are contemplated such as a system embodied as aspecial purpose processor. Although the steps described below aredescribed as being executed by a processor, the steps are notnecessarily executed by a same processor. In other words, at least oneprocessor may execute the steps described below with regard to FIG. 4.

FIG. 4 is a flowchart illustrating a method for preventing an overtemperature condition while charging a device according to at least oneexample embodiment. As shown in FIG. 4, in step S405 a bus voltage(V_(bus)) on a first (e.g., cable assembly connector) side of a contactof a connector interface is detected. For example, V_(bus) on theconnector B side is detected or sensed as an input to the current senseamplifier 330.

In step S410 a bus voltage (V_(bus)) on a second (e.g., device) side ofthe contact of the connector interface is detected. For example, V_(bus)on the computing device 225 side is detected or sensed as an input tothe current sense amplifier 330.

In step S415 a voltage drop across the contact of the connectorinterface is determined. For example, the current sense amplifier 330can sense a current associated with both V_(bus) on the connector B side(e.g., as V_(sbu)) and V_(bus) on the computing device 225 side andoutput a voltage based on the V_(bus) on the connector B side (e.g., asV_(sbu)) and V_(bus) on the computing device 225 side as a voltage drop(or voltage difference) representing the voltage drop across the contactof the connector interface.

In step S420 the voltage drop is compared to a reference (or threshold)value. For example, the voltage drop across the contact of the connectorinterface can be monitored to determine if it rises above the referencevalue. In an example implementation, the comparator 335 is coupled tothe output of the current sense amplifier 330 and a reference terminal.The comparator 335 is configured to compare the value detected output bythe current sense amplifier 330 to a value associated with the referenceterminal. Each value can be a voltage value or level.

In step S425 whether the voltage drop is less than the reference valueis determined. In response to determining the voltage drop is less than(or equal to) the reference value, in step S430, drawing current fromthe power source is continued. In response to determining the voltagedrop is greater than the reference value, in step S435 a signal iscommunicated to a processor. For example, the comparator 335 cancommunicate a signal (e.g., an interrupt signal) to the processor 305.

In step S440 the current draw from the power source is reduced. Forexample, in response to receiving the interrupt signal, the processor305 can reconfigure or modify (e.g., send an instruction to) theswitching charger 310 to draw less current and/or to the bypass switch315 to draw less current. The processor 305 can reconfigure theswitching charger 310 and/or the bypass switch 315 to at least one ofchange the maximum current draw, change the amount of current to drawand terminate the current draw.

Although not shown in FIG. 4 described above, if at any time the powerconverter 205 is disconnected from the computing device 225 theprocessor 305 can reconfigure the switching charger 310 and/or thebypass switch 315 to stop drawing current. In other words, detachment ofthe cable 215 can terminate the method steps described with regard toFIG. 4.

Various implementations of the systems and techniques described here canbe realized in digital electronic circuitry, integrated circuitry,specially designed ASICs (application specific integrated circuits),computer hardware, firmware, software, and/or combinations thereof.These various implementations can include implementation in one or morecomputer programs that are executable and/or interpretable on aprogrammable system including at least one programmable processor, whichmay be special or general purpose, coupled to receive data andinstructions from, and to transmit data and instructions to, a storagesystem, at least one input device, and at least one output device.Various implementations of the systems and techniques described here canbe realized as and/or generally be referred to herein as a circuit, amodule, a block, or a system that can combine software and hardwareaspects. For example, a module may include the functions/acts/computerprogram instructions executing on a processor (e.g., a processor formedon a silicon substrate, a GaAs substrate, and the like) or some otherprogrammable data processing apparatus.

Some of the above example embodiments are described as processes ormethods depicted as flowcharts. Although the flowcharts describe theoperations as sequential processes, many of the operations may beperformed in parallel, concurrently or simultaneously. In addition, theorder of operations may be re-arranged. The processes may be terminatedwhen their operations are completed, but may also have additional stepsnot included in the figure. The processes may correspond to methods,functions, procedures, subroutines, subprograms, etc.

Methods discussed above, some of which are illustrated by the flowcharts, may be implemented by hardware, software, firmware, middleware,microcode, hardware description languages, or any combination thereof.When implemented in software, firmware, middleware or microcode, theprogram code or code segments to perform the necessary tasks may bestored in a machine or computer readable medium such as a storagemedium. A processor(s) may perform the necessary tasks.

Specific structural and functional details disclosed herein are merelyrepresentative for purposes of describing example embodiments. Exampleembodiments, however, may be embodied in many alternate forms and shouldnot be construed as limited to only the embodiments set forth herein.

It will be understood that, although the terms first, second, etc. maybe used herein to describe various elements, these elements should notbe limited by these terms. These terms are only used to distinguish oneelement from another. For example, a first element could be termed asecond element, and, similarly, a second element could be termed a firstelement, without departing from the scope of example embodiments. Asused herein, the term and/or includes any and all combinations of one ormore of the associated listed items.

It will be understood that when an element is referred to as beingconnected or coupled to another element, it can be directly connected orcoupled to the other element or intervening elements may be present. Incontrast, when an element is referred to as being directly connected ordirectly coupled to another element, there are no intervening elementspresent. Other words used to describe the relationship between elementsshould be interpreted in a like fashion (e.g., between versus directlybetween, adjacent versus directly adjacent, etc.).

The terminology used herein is for the purpose of describing particularembodiments only and is not intended to be limiting of exampleembodiments. As used herein, the singular forms a, an, and the areintended to include the plural forms as well, unless the context clearlyindicates otherwise. It will be further understood that the termscomprises, comprising, includes and/or including, when used herein,specify the presence of stated features, integers, steps, operations,elements and/or components, but do not preclude the presence or additionof one or more other features, integers, steps, operations, elements,components and/or groups thereof.

It should also be noted that in some alternative implementations, thefunctions/acts noted may occur out of the order noted in the figures.For example, two figures shown in succession may in fact be executedconcurrently or may sometimes be executed in the reverse order,depending upon the functionality/acts involved.

Unless otherwise defined, all terms (including technical and scientificterms) used herein have the same meaning as commonly understood by oneof ordinary skill in the art to which example embodiments belong. Itwill be further understood that terms, e.g., those defined in commonlyused dictionaries, should be interpreted as having a meaning that isconsistent with their meaning in the context of the relevant art andwill not be interpreted in an idealized or overly formal sense unlessexpressly so defined herein.

Portions of the above example embodiments and corresponding detaileddescription are presented in terms of software, or algorithms andsymbolic representations of operation on data bits within a computermemory. These descriptions and representations are the ones by whichthose of ordinary skill in the art effectively convey the substance oftheir work to others of ordinary skill in the art. An algorithm, as theterm is used here, and as it is used generally, is conceived to be aself-consistent sequence of steps leading to a desired result. The stepsare those requiring physical manipulations of physical quantities.Usually, though not necessarily, these quantities take the form ofoptical, electrical, or magnetic signals capable of being stored,transferred, combined, compared, and otherwise manipulated. It hasproven convenient at times, principally for reasons of common usage, torefer to these signals as bits, values, elements, symbols, characters,terms, numbers, or the like.

In the above illustrative embodiments, reference to acts and symbolicrepresentations of operations (e.g., in the form of flowcharts) that maybe implemented as program modules or functional processes includeroutines, programs, objects, components, data structures, etc., thatperform particular tasks or implement particular abstract data types andmay be described and/or implemented using existing hardware at existingstructural elements. Such existing hardware may include one or moreCentral Processing Units (CPUs), digital signal processors (DSPs),application-specific-integrated-circuits, field programmable gate arrays(FPGAs) computers or the like.

It should be borne in mind, however, that all of these and similar termsare to be associated with the appropriate physical quantities and aremerely convenient labels applied to these quantities. Unlessspecifically stated otherwise, or as is apparent from the discussion,terms such as processing or computing or calculating or determining ordisplaying or the like, refer to the action and processes of a computersystem, or similar electronic computing device, that manipulates andtransforms data represented as physical, electronic quantities withinthe computer system's registers and memories into other data similarlyrepresented as physical quantities within the computer system memoriesor registers or other such information storage, transmission or displaydevices.

Note also that the software implemented aspects of the exampleembodiments are typically encoded on some form of non-transitory programstorage medium or implemented over some type of transmission medium. Theprogram storage medium may be magnetic (e.g., a floppy disk or a harddrive) or optical (e.g., a compact disk read only memory, or CD ROM),and may be read only or random access. Similarly, the transmissionmedium may be twisted wire pairs, coaxial cable, optical fiber, or someother suitable transmission medium known to the art. The exampleembodiments are not limited by these aspects of any givenimplementation.

Lastly, it should also be noted that whilst the accompanying claims setout particular combinations of features described herein, the scope ofthe present disclosure is not limited to the particular combinationshereafter claimed, but instead extends to encompass any combination offeatures or embodiments herein disclosed irrespective of whether or notthat particular combination has been specifically enumerated in theaccompanying claims at this time.

What is claimed is:
 1. A device comprising: an interface including aplurality of contacts, the interface being configured to couple a powersource to the device, the plurality of contacts including: at least onefirst contact configured to couple a voltage bus of the power source toa voltage bus of the device, and at least one second contact configuredto couple the voltage bus of the power source to a secondary bus of thedevice; and a detector configured to determine a contact resistance ofthe at least one first contact based on a first current associated withthe voltage bus and a second current associated with the secondary bus.2. The device of claim 1, wherein the detector is further configured to:generate a voltage drop generated based on a current associated with thevoltage bus and a current associated with the secondary bus; determineif the voltage drop exceeds a reference value; and in response todetermining the voltage drop exceeds the reference value, trigger areduction of a current drawn from the power source.
 3. The device ofclaim 1, wherein the detector includes: a current sense amplifierconfigured to generate a voltage drop generated based on a currentassociated with the voltage bus and a current associated with thesecondary bus; and a comparator configured to: compare the voltage dropto a reference value, and communicate a result of the comparing of thevoltage drop to the reference value to a processor.
 4. The device ofclaim 1, further comprising: a battery; a switching charger configuredto reduce a voltage to a level supported by the battery; a bypass switchconfigured to bypass the switching charger; and a processor configuredto select the switching charger or the bypass switch based on a voltageassociated with the power source.
 5. The device of claim 1, wherein theinterface uses a universal serial bus (USB) TYPE-C standard.
 6. Thedevice of claim 1, further comprising: a processor configured to:determine an amount of current to draw from the power source based on acapability signal received from the power source, instruct one of aswitching charger or a bypass switch to draw the amount of current fromthe power source, and instruct one of the switching charger or thebypass switch to reduce the amount of current to draw from the powersource based on a communication received from the detector.
 7. Thedevice of claim 1, further comprising: a processor configured to:instruct one of a switching charger or a bypass switch to draw currentfrom the power source, and instruct one of the switching charger or thebypass switch to terminate the drawing of the current from the powersource based on a communication received from the detector.
 8. Thedevice of claim 1, the secondary bus includes a high impedance input tothe detector.
 9. The device of claim 1, further comprising: a processorconfigured to cause a coupling and decoupling of a voltage bus traceassociated with the voltage bus of the power source to the secondary busof the device.
 10. A method comprising: detecting a bus voltage on afirst side of a contact of a connector interface; detecting the busvoltage on a second side of the contact of the connector interface;determining a voltage drop based on the bus voltage on the first side ofthe contact and the bus voltage on the second side of the contact; andreducing a current drawn from a power source based on the voltage drop.11. The method of claim 10, further comprising: comparing the voltagedrop to a reference voltage.
 12. The method of claim 10, wherein thevoltage drop corresponds to a contact resistance of the contact.
 13. Themethod of claim 10, wherein the connector interface uses a universalserial bus (USB) TYPE-C standard.
 14. The method of claim 10, whereinthe contact is a first contact, the method further comprising: one ofcoupling or decoupling the bus voltage to a second contact on the secondside of the contact.
 15. The method of claim 10, further comprising:comparing the voltage drop to a reference value, and communicating aresult of the comparing of the voltage drop to the reference value to aprocessor.
 16. The method of claim 10, determining if the voltage dropexceeds a reference value; and in response to determining the voltagedrop exceeds the reference value, triggering the reducing of the currentdrawn from the power source.
 17. The method of claim 10, determining ifthe voltage drop exceeds a reference value; and in response todetermining the voltage drop exceeds the reference value, terminatingthe current draw from the power source.
 18. The method of claim 10,further comprising: selecting one of a switching charger or a bypassswitch for use in charging a battery based on a voltage associated withthe power source, wherein the switching charger is configured to reducea voltage to a level supported by the battery, and the bypass switch isconfigured to bypass the switching charger.
 19. A non-transitorycomputer-readable storage medium having stored thereon computerexecutable program code which, when executed on a computer system,causes the computer system to perform steps comprising: detecting a busvoltage on a first side of a contact of a connector interface; detectingthe bus voltage on a second side of the contact of the connectorinterface; determining a voltage drop based on the bus voltage on thefirst side of the contact and the bus voltage on the second side of thecontact; and reducing a current drawn from a power source based on thevoltage drop.
 20. The method of claim 10, wherein the voltage dropcorresponds to a contact resistance of the contact.